Conventional clamshell type laptop computers have an upper display unit rotatably connected to a main module that holds a processor unit, a keyboard, a pointing device, data storage devices, and other peripherals. A hinge positioned at a bottom margin of the display unit connects the display unit to the main module near a rear margin of the main module. Rotation of the display unit about the hinge determines the viewing angle of the display. In normal operation, the display unit is typically rotated to an obtuse angle relative to the keyboard. At a comfortable viewing angle, in which the display faces slightly upward, the display unit extends rearward, away from the main module and the hinge. Adjustment of the display unit to the comfortable viewing angle in shallow workspaces, such as passenger seats of commercial airlines, requires the keyboard to be positioned uncomfortably close to the user. Furthermore, when an airline passenger seat immediately in front of the user is reclined, it can be very difficult for the user to view the display. Use in constrained spaces is especially problematic for laptop computer displays utilizing active matrix LCD technology, which is optically directional and has a limited useful viewing angle.
Several proposed laptop computer designs include secondary hinges that allow the display to be rotated to a comfortable viewing angle. For example, U.S. Pat. No. 6,006,243 of Karidis describes a tri-fold laptop computer including a top-hinged display screen that rotates outwardly from an outer display case portion of the housing and into a presentation position. In the presentation position, however, the display screen blocks access to the keyboard of the laptop computer.
U.S. Pat. No. 6,076,786 of Meyer describes a laptop computer having a display adjustment mechanism that is enclosed in a compartment behind a display screen of the laptop computer when the display screen is in a lowered position. The adjustment mechanism is hinged at its bottom end to a rear margin of a keyboard module. Fully extending the display screen above the adjustment mechanism reveals a secondary hinge that allows the display panel to pivot rearward from the secondary hinge and into a more comfortable viewing position. Because the adjustment mechanism is enclosed within the compartment behind the display screen, when lowered, any articulation of the secondary hinge requires the display screen to be fully extended above the adjustment mechanism. This fully extended position is not always desirable, for example, when using the laptop computer on a tall table. Fully extending the display screen also raises the center of gravity of the laptop computer, thereby making it more prone to tipping.
U.S. Pat. No. 6,005,767 of Ku et al., U.S. Pat. No. 5,548,478 of Kumar et al., and U.S. Pat. No. 5,255,214 of Ma all describe laptop computers with displays that are movable to an inclined position for use. All include a laptop computer keyboard that extends up to a front margin of the computer so that no part of the housing is available for use as a wrist rest. The lower section of each of these computers extends several inches rearward of the keyboard to accommodate the display. In an airline passenger seat, this configuration requires the keyboard to be placed several inches closer to the user than would be possible with a conventional laptop computer keyboard. Furthermore, placement of the keyboard at the front margin of the computer does not accommodate a pointing device, such as a touch pad or trackball, in front of the keyboard, as is done in many conventional laptop computers.
Thus, a need exists for an improved display mounting for a laptop computer that facilitates orientation of the display screen at a comfortable viewing angle, even when used in depth-constrained spaces such as airline passenger seats, and without requiring modification to the lower portion of the laptop computer.